Switching apparatus for pumping plants comprising a. plurality of electrically-operated pumps



Aug. 31 1926 SWITCHING APPARATUS FOR PUMPING PLANTS COMPRISING APLURALITY OF ELECTRICALLY OPERATED PUMPS 4 Filed April A. 1925 2Sheets-$heet 1 Patented Aug. 31, 1926.

NHED STATES ERNST VOGEL, F STOCKERAU, AUSTRIA.

SWITCHING APPARATUS FOR PUME'ING PLANTS COMPRISING A PLURALITY OFELECTRICALLY-OPERATED PU'IYIIPS.

Application filed April 4, 19-25, Serial No. 20,869, and in AustriaMarch 7, 1924.

Arrangements are already known for operating pumping plants comprisingtwo or more pumps having different discharge volumcs and for the mostpart also different resistance heads in such a manner that one of thesepumps, which corresponds to the water-consumption for the time being andto the associated resistance head is set in operation by hand orautomatically and the pump that has previously been in operation for asmaller or greater water-consumption and a corresponding resistance headis thrown out of operation.

In the case of the arrangement hitherto known the disconnecting of onepump and the starting of a second are effected one after the other inpoint of time, so that during the changing over, even though only for ashort time, no pump is operative. Fromthis there arise variousdisadvantages, for example a fall of pressure in the common air vessel,and so forth.

This invention relates to switching apparatus whereby the starting andcutting out of the pumps in question are effected simultaneously.

In the drawing, Figures 1 and 2 show one constructional form of theswitching apparatus in two different positions, for example for fourpumps, and Figure 3 a hydraulic controlling piston serving to actuatethe switching apparatus automatically, in a central vertical section.

In Figures 1 and 2 the conductors a a 6,, 7)., and c 0 leading to theelectric pump-driving motors 21, 22 and 23 respectively, each comprisetwo contacts and 31, with lever-like switches 32 and 33. The conductor(Z (Z leading to the last motor 24, on the contrary, comprises only onecontact 31, with a switch 33. Each two of these switches, belonging totwo adjacent circuits, are connected with one another by arms 33 and 32and a link or guide rod 34 in such a way that they always take upopposite positions, that is to say that one switch is opened if thesecond switch is closed. The one switch 33 of the first motor 21 remainsover as an uncoupled switch,

The coupled switches and the single switch, for the successive actuationthereof, are provided with a device consisting of a fork 35. These forksare subject to the action of the stops 36, 37, 38 and 39 on a switchingrod 40. This rod can be shifted backwards and forwards from point topoint in its longitudinal direction within four positions;

In the case of the position shown in Figure 1 the pump motor 21 isswitched on for the smallest waterwonsumption, because both switches 32,33.; close the circuit a 66 The switch 32 was closed already a'ndtheswitch 33 became closed owing to the action of the stop 36 on the fork35. All the re maining circuits are interrupted at one point andtherefore the pump motors in connection therewith are switched off.

1f the consumption of water rises, a longitudinal displacement of therod 40 in the direction of the arrow is effected. The next stop 37 thenacts on the associated fork 35, whereby the switch 33 of the circuit forthe pump 22 is moved into the closed position,

and at the same time the switch 32 of the pump 21, which is coupledthereto, is moved into the open position (Figure 2). The pump 21 istherefore cut out and at the same time the pump 22 is started, thelatter result being on account of the fact that its second switch 32 isin the closed position.

Upon the consumption of water rising further the stop 38 acts on theassociated fork whereby the pump 22 i s cutout and the pump 23 issimultaneously started.

Upon a still further increase in the water consumption the pump 23 iscut out by the stop 39 and the largest pump 24' is started by rockingthe single switch 33 into the contact position.

If on the other hand, at any switching position, the consumption ofwater falls off, for example with the pump 22' switched on (Figure 2),the switching rod 1O is shifted in the direction opposite to the arrowand by the stop 37 the pump 22 is switched off but the pump 21 isswitched on.

The member 40 of this switching apparatus may be adjusted either by handor an tomatically. The automatic adjustment may be effected by anysuitable means, subjected to the action of the varying water-consumption. As such means there may come into consideration hydraulicregulating pistons, which are actuated by the varying quantity of thewater flowing away from the common air vessel of the pumps into theconsumption network per unit of time, or pressure gauges on the said airvessel, or floats in the air vessel.

In Figure 3 is illustrated a hydraulic control piston in a duplicatedarrangement serving for the adjustment of the controlling organ e0.

In each cylindrical tube 0, which is preferably conical at the bottom, adisplacer or regulator piston (Z is movably arranged, which only leavesa small gap open at its periphery for the passage of water. Theregulator piston preferably forms a hollow body, which tapers offtowards both ends, is open on one end face, and is guided in the tube 0by means of the longitudinal ribs cl occupying the central part of itslength. At the bottom of each hollow body (Z is fastened a bolt c, towhich at C a link or guide rod 0 is attached in each case. These linkslead to a double-armed lever Z mounted fast on the control shaft m. Thevcontrol shaft emerges from the pipe bend a connecting the two tubes 0, 0through a stuffing box, and carries at its free end a weighted lever a".y

The water passes out of the air vessel (not shown) which is common toall the pumps, into the casing, passes both dis placers d, in the gap ofwhich an increase in velocity occurs, and flows at b into theconsumption mains. In correspondence with this increased velocity thereis in front of each piston, relatively to the direction of motion of thewater, a higher pressure acting than behind the piston, which, in thecase of the minimum quantity flowing, is so small that the weight levera: and the displacer d occupy the position I. With an increase in thevolume flowing through, however, the regulatorpistons adjust themselvesinto the positions II, III, and IV in succession, the weighted leveraccordingly takes up in succession the positions II, III ant IV andconsequently opposes to the increasing pressure in front of the piston acorrespondingly increasing opposing torque, whereby the pistons (Z areheld in the corresponding positions. Owing to this the control lever pwhich is mounted fast on the control shaft m and which has to transmitthe controlling of the electrical part of the switch from one pump toanother, also ta res up different positions. The control lever 29, bymeans of the slot guide 0, can actuate the roller 41 of the switchingrod 40.

hat I claim is:

1. In a fluid supply system, a plurality of pumps, electric motors fordriving said pumps, one for each pump, a circuit control ling device foreach motor, and means op erable upon a predetermined change in the rateof consumption of the fluid in said supply system for simultaneouslyclosing the circuit controlling device for one of said motors andopening the circuit controlling device for another of said motors.

2. In a fluid supply system, a plurality of pumps, each of said pumpshaving a capacity differing from the capacities of the others of saidpumps, electric motors for driving said pumps, one for each pump, acircuit controlling device for each motor, and means operable upon apredetermined change in the rate of consumption of the fluid in saidsupply systemfor simultaneously opening the circuit controlling de iceof the motor for one of said pumps and closing the circuit controllingdevice of the motor for another of said pumps.

3. A fluid supply system as claimed in claim 2, in which the pumpbrought into operation upon change in the rate of consumption is ofgreater capacity than the pump whose motor circuit has been interruptedwhen the pressure decreases, and of lesser capacity when the pressureincreases.

l. A fluid supply system as claimed in claim 1, in combination with ahydraulic piston regulator in the supply system for operating thecircuit controlling devices.

5. In a fluid supply system, a plurality of pumps, electric motors fordriving said pumps, one for each pump, a pair of switches for one ofsaid motors, said motor being driven only when both of said switches areclosed, a switch for another of said motors, said switch being open whensaid first motor is being driven, and means for simultaneously closingthe switch for said second motor and opening one of the switches forsaid first motor.

6. A fluid supply system as claimed in claim 5, in which the switch forsaid second motor is connected to the simultaneously moving switch forsaid first motor, and said means is provided with a projection adaptedto engage a forked arm on one of said switches.

In witness whereof I have hereunto signed my name.

ERNST VOGEL.

